Precision Armament AFAB: First Impression

Nearly all of the gifts my wife bought me for Christmas were shooting related, and I plan on reviewing a few of them. One of those gifts is a new muzzle device from Precision Armament.

The AFAB, which stands for Advanced Flash Arresting Brake, is the second generation of the device and replaced the now-discontinued AFAB-mini. They revised the design using lessons learned after developing the EFAB, or Enhanced Flash Arresting Brake, which they developed after the original AFAB-mini. Most of the changes relate to better flash suppression. Precision Armament’s M4-72 Compensator was the best performer in both of TTAG’s Muzzle Brake Shootouts, so the company knows what it’s doing (the AFAB-mini performed slightly worse, but it is not a dedicated compensator).

The first thing I will say about the AFAB is that I don’t know how they are charging the price they are for it. At $109, it’s not an inexpensive item. But the amount of machine work and polish that has gone into this thing is just flat-out impressive.

I have often seen the AFAB compared to the Knights Armament Triple Tap, but this really comes down to similarity of appearance due to the square pattern on the outside. The internals are very different. The KAC device is closer to the Battlecomp in that the inside of the device is hollow. The vents on the KAC device run in lines from front to back, and the waffle pattern comes from grooves cut around the circumference of the device.

On the other hand, the AFAB’s squares are all individually cut. There are circular drilled vents at the corner of each square. From what I’ve read, the square pattern helps with some of the flash mitigation. The very top and bottom of the device lack any vents. Vents on the top would contribute to the downward push noted in devices like the Battlecomp. Vents on the bottom would increase muzzle jump and dust signature.

On the inside of the AFAB, you will see a series of concentric blast chambers. This design helps trap expanding gasses and force them out of the vent holes, better assisting with muzzle stability.

A cutaway drawing from Precision Armament showing the internal structure of the AFAB

The end of the device has three tines, like many other popular flash hiders on the market. Being a muzzle brake, I don’t expect this to suppress flash as well as something like my AAC Blackout, but the internet buzz is that it does a comparable job to the standard A2 birdcage.

I will be installing the AFAB in the next week or so. I’ve grown tired of paying my local gun shop to do it, so I ordered a Magpul Armorer’s Wrench and Geissele Reaction Rod (found them on sale). I’ve yet to dabble in assembling upper components, so this may be a bit of an adventure.

Precision Armament explicitly tells you NOT to use crush wafers when installing this device. The internal blast baffles and exit hole at the front have very tight tolerances, like sound suppressors, and any misalignment may result in the bullet impacting. Instead, they suggest using their shim system (sold separately) or a peel washer. I purchased the shim kit, which is apparently good for installing about 9 different brakes- so it’s not a one time deal. If they work out, I will probably revisit the devices installed on my other uppers.

The kit comes with about 18 shims of different thicknesses. They are marked to let you know where they are in that range (thinnest to thickest). Each increase in the series accounts for about 20 degrees of rotation of the device. You only use a single shim for the install. Simply choose the shim that gives you about 10-20 degrees left of travel when hand tight, and then torque the device appropriately (10-20 ft/lb). I will be using some Rocksett for extra assurance.

I will install the AFAB on my 20″ upper. I expect that it will make an already incredibly smooth-shooting rifle perform even better. I look forward to seeing what it can do.

And yes, I know that muzzle brakes are not allowed on rifles used for CMP competition. However, there aren’t any CMP matches anywhere near me. In any case, I will probably end up building a separate rifle for CMP matches anyway.